[Twisted-Python] OT - adbapi, connection timeouts, mysql - OT

Gabriel Rossetti gabriel.rossetti at arimaz.com
Wed Jul 22 00:32:12 MDT 2009


Hello Werner,

Thanks for your idea, I will give it a try if my current "fix" doesn't 
work well (reconnecting if I get a connection lost exception and 
re-running the query).

Gabriel

Werner Thie wrote:
> Hi Gabriel
>
> had the same problem, solved it by having keepalive() called in a 
> LoopingCall(), MySQL sitting at defaults timingwise.
>
> DB_DRIVER = "MySQLdb"
>
> USERDB_ARGS = {
>    'host': '',
>    'db': '',
>    'user': '',
>    'passwd': '',
>    'cp_reconnect': True
> }
>
> storekeeper = StoreKeeper(DB_DRIVER, **USERDB_ARGS)
>
> ka = task.LoopingCall(storekeeper.store.keepAlive)
> ka.start(300)
>
> class StoreKeeper(object):
>    def __init__(self, dbapiName, **params):
>      self.store = Store(dbapiName, **params)
>
>    def dbdisconn(self, reason):
>      print 'db disconnected for ', reason
>
>    def keepAlive(self):
>      d = self.store.runQuery('SELECT 1')
>      d.addErrback(self.dbdisconn)
>
>
> #with store being something like:
>
> class Store(object):
>    def __init__(self, dbapiName, **params):
>      self.__pool   = adbapi.ConnectionPool(dbapiName, **params)
>      print self.__pool.__getstate__()
>      self.runOperation('SET autocommit = %s', 1)
>
>    def runQuery(self, query, *args):
>      d = self.__pool.runInteraction(self.mapQuery, query, args)
>      return d
>
>    def mapQuery(self, curs, query, *args):
>      try:
>        curs.execute(query, *args)
>      except adbapi.ConnectionLost:
>        print
>        print '++++++++++++ rerunning query'
>        print
>        curs.execute(query, *args)                    #simply resend 
> query, assuming cp_reconnect=True
>      result = curs.fetchall()
>      columns = [d[0] for d in curs.description]
>      return [dict(zip(columns, r)) for r in result]
>
>    def runOperation(self, query, *args):
>      d = self.__pool.runOperation(query, args)
>      return d
>
>    def runInteraction(self, fun, queries=(), args=()):
>      d = self.__pool.runInteraction(fun, queries, args)
>      return d
>
>
> HTH, Werner
>
> Gabriel Rossetti wrote:
>   
>> Hello everyone,
>>
>> I have been experiencing the ConnectionError with adbapi & 
>> cp_reconnect=True. I know that because of the cp_reconnect=True param 
>> tha is reconnects and that the query is not re-run. I have written some 
>> code that should re-run the query in that case (if I get a Failure back 
>> because of a ConnectionError), but it doesn't seem to work. My question 
>> is if anyone knows how to make mysql's idle timeouts shorter so that I 
>> can debug my code? I searched google and the mysql site with no luck.
>>
>> thank you,
>> Gabriel
>>
>> _______________________________________________
>> Twisted-Python mailing list
>> Twisted-Python at twistedmatrix.com
>> http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
>>     
>
>
> _______________________________________________
> Twisted-Python mailing list
> Twisted-Python at twistedmatrix.com
> http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
>   




More information about the Twisted-Python mailing list